Is this the summer of sharks?

PUBLISHED : Saturday, 02 June, 2001, 12:00am
UPDATED : Saturday, 02 June, 2001, 12:00am

AFTER THREE UNCONFIRMED sightings of up to 10 primordial predators in Deep Water Bay recently, a city's collective fear of sharks has been resurrected. Sunday junk cruise parties are making excuses not to swim. Cocktail conversation recollects Australian shark hunter Vic Hislop's unintentionally comic attempt at hunting local man-eaters in the mid-1990s. Even surfers are hesitant about tempting fate.


Is it going to be a shark summer?


Hong Kong sharks have an exceedingly high kill rate, wreaking unwitting revenge on a city whose insatiable appetite for shark's fin soup is leading to the species' demise. Since 1991, all six confirmed attacks by sharks on humans were fatal, compared with a global statistical average of 15 per cent, according to the International Shark Attack Files (ISAF). For the decade of the 90s, only Brazil, Australia, South Africa and Reunion Islands, respectively, recorded more deaths, according to the ISAF.


Also Hong Kong sharks are exceptionally prone attacking human victims. Worldwide, Hong Kong rounded out the top 10 in number of attacks by region in the past decade (1990-2000). About 50 people are attacked by sharks annually, says the ISAF, whereas in 1995, three people were killed in a fortnight in the waters off Sai Kung alone.


'For a period, Hong Kong was the most unsafe place on the planet for shark attacks,' says Keith Wilson, a senior fisheries officer with the Agriculture, Fisheries and Conser-vation Department.


But that doesn't seem to be the case any more, according to marine biologist Andrew Cornish. 'Basically, for all intents and purposes, sharks are extinct in Hong Kong,' he says. In the course of 1,000 dives over five years in researching a book he co-authored, Reef Fish Of Hong Kong, Cornish says he's seen only one shark. It was a nurse shark, a small-mouthed, bottom-dwelling, crustacean-eating, bunny rabbit of a predator spotted in Mirs Bay.


Ultimately, biologists' knowledge of some 350 species of shark is a drop in the ocean, and in Hong Kong, even less so. It doesn't make for much of a doctorate thesis if you can't find anything to study, says Cornish.


What is known, however, is that all local attacks have historically occurred when waters warm up to 24 degrees Celsius or more, a temperature recently reached at local beaches. As of last weekend, many beaches hit 26 degrees, though hotter doesn't mean more shark activity.


The warming precipitates a South China Sea change, a theory put forth by George Burgess, director of the International Shark Attack Files based in Florida, when the Government commissioned him to fly out and study Hong Kong waters in 1995, the year of the last reported shark-attack death.


Burgess and other local marine biologists believe that as local waters heat up in the spring, rays, turtles and equatorial tropical fish - like yellowfin tuna and Spanish mackerel - extend their range and venture north. The schools are pursued by sharks, especially migratory tiger sharks, a notorious maneater only second to the great white.


A temperature of 24 degrees seems to serve as a catalyst to movement for both the tiger and great white shark. Tiger sharks only inhabit waters 24 degrees and warmer, and great whites only inhabit waters 24 degrees and cooler. As such, it's never been concluded with certainty which predator was responsible for at least six deaths in the 90s. Was it a tiger coming, or a great white going?


The recent macabre history began in 1991, when a woman was killed at Silverstrand Beach at Clear Water Bay. Days later, television cameras from a helicopter captured a five-metre 'thick-barrelled shark' prowling in the vicinity, says Wilson. 'It was too big for a bull [shark]. It had to be either a tiger or great white.'


In 1993, beginning in early June, at least two people fell victim. In 1995, three people were killed in Clearwater Bay within a fortnight, beginning in late May.


'I feel sorry for big sharks coming through because there's nothing for them to eat,' says Charles Frew, of Asiatic Marine Limited, which runs educational shark-diving expeditions worldwide. 'So unfortunately they might have to go for a human.'


Eventually, post-mortems did 'strongly suggest' tiger sharks, says Wilson. While a great white shark has sharp, triangular teeth, a tiger shark has smaller teeth that work like a blade saw when shaking prey.


The brash Australian shark hunter Vic Hislop, who caught only a cold and food poisoning when he was flown out to capture the maneaters in 1993, not surprisingly took a contrarian stance: he believed the predators were great whites.


His theory gained some credence years later when US marine biologists captured on videotape great whites returning annually to feed at the same location. Similarly, local experts thought the sharks may have developed a homing pattern for Silverstrand Beach.


Frew deferred when asked to proffer an opinion on what species of shark instigated the attacks. 'Speculation starts wars,' he says.


Aside from the time of year, one of the greatest common denominators was that most attacks occurred in Clear Water Bay, possibly because the sharks were pursuing an abundance of prey there. The seasonal butterfly ray is known to congregate in the summer in Port Shelter, says Cornish, and rays in general are known as a significant part of a tiger shark's diet.


Hong Kong has a 'reasonably healthy' population of rays, says Cornish, because they've never been commercially targeted and prefer a sandy substrate, which is common here.


Another reason why sharks might target Sai Kung is because substantial fish farms in the region throw refuse, like fish guts and blood, into the water, creating a sort of maritime McDonalds, Brian Morton, a former director of the Swire Institute of Marine Science, commented in 1995. Morton also thought the sharks responsible for the Sai Kung attacks were resting at night in underwater caves at Po Toi islands. That there's been no attacks since 1995 also lends credence to a theory that it was the same shark or sharks responsible for the killings. It's a theory supported by Rommy Cheung, a local diver of 20 years. As the scuba-diving course director at International Elite Divers Training Centre in Kowloon, it was Cheung's team who was sponsored by Apple Daily in 1995 to build a shark cage and search for maneaters. Using the $100,000 contraption, Cheung says that in more 50 dives, they failed to sight any sharks.


Aside from the time of year when the sharks have attacked - most commonly early June - the only other pattern local experts have noted is that the attacks occurred in odd years. With the reported sightings weeks ago at Deep Water Bay, will this be the summer of sharks? 'It's 2001,' says Wilson, 'will the attacks begin all over again?'


Says Cornish: 'There's no way of telling until it happens.'


Regarding this year's scare, all the experts actually question the Deep Water Bay sightings. For one, they consider it an unusual locale for a shark to be roaming. Second, they cite other species, such as juvenile pink dolphins, which are brown (though their parents are usually never far away), finless porpoise, or cobia, fish that grow up to 1.5 metres, that could be mistaken for a shark to an uneducated eye.


Historically, Hong Kong did have sustainable, commercial shark fisheries. Large hammerheads of up to 4.5 metres long and black-tip reef sharks were commonly pulled from the waters at the Pedro Blanco rock pinnacles about 80km due east of Hong Kong, and at Lemas Islands, a chain only 11km south of the city, says Frew, who has dived with and filmed great whites off South Africa without the safety of a shark cage. Black tips were also known to breed in the Pearl River delta north of Chep Lap Kok airport, Frew says.


As the sharks were fished to death for their fins about 50 years ago, Hong Kongers have little memory of sharks other than 'the odd, huge shark that kills, rather than recognising them as part of the ecosystem in which 99 out of 100 are not harmful at all', says Frew.


As a result of these rogue attacks, he concludes that Hong Kongers have never come to terms with sharks. 'This perception may never change unless we can convince the younger generation that sharks have important roles in the ocean and should be respected as top predators and not demonised as mindless killers,' he has said.


Perhaps mirroring an ignorant public, the Government, in what passes for a typical knee-jerk response - throwing money at a problem rather than trying to remedy it by taking time to understand and solve it logically - first installed shark nets in 1994 at Silverstrand Beach, Clear Water Bay Second Beach and Kadoorie Beach in Tuen Mun.


At the time, the shark nets were controversial because they were of a different type than those used in Australia or South Africa. The nylon meshing of Hong Kong's nets has a diameter of two and a half centimetres compared to 18cms employed elsewhere.


Though they had little track record at the time, the smaller diameter mesh nets are now recognised as more environmentally friendly as they result in less fewer smaller fish being caught, says Kenneth Chan, managing director of Maritime Mechanic, the company that first won a government contract to install nets at local beaches.


Maritime Mechanic's founder, Norwegian Harald Kvam, was one of the stronges advocates of studying local sharks. Kvam was known to rush to beaches where sharks had been sighted to swim outside the net with the hope of filming them. 'He was very gung-ho and not particulary safety-conscious,' says Wilson.


Kvam began his own private study after the spate of attacks in 1995 and invested more than US$1 million in a sonar tracking system and a remote-operated vehicle capable of plumbing depths of 328 metres. In 1997, he searched around Port Shelter off Sai Kung but couldn't find any sharks to tag with his radio transmitters. 'It was quite disappointing,' says Chan. A year later, Kvam, 41, died in a diving accident in Papau New Guinea when, on the last dive of the day, he inadvertently filled his tank with pure oxygen and went into convulsions. 'After Harald passed away, we lost the human resources to carry on the project,' says Chan.


And though the Government formed a committee on shark prevention after the 1993 attacks, that group has been likewise sidelined, in part because private enterprise - meaning Kvam - was taking the lead. It is likely also because there's been no fatalities since 1995, fewer sightings and protective nets are in place.


'Even if we can't see them, I believe they're around,' says Chan, adding that underwater visibility averages less than five metres. 'They have been here in the past. Why would we not think they're in the water now?'


At present, 32 beaches are equipped with shark nets at an estimated cost of $28 million, and an additional $28 million a year to maintain, yet there has never been a substantive study on sharks, scientists complain.


Yvonne Sadovy, an associate professor in the Department of Ecology and Biodiversity at the University of Hong Kong, worked with Burgess on the 1995 brief. They recommended an 18-month study using sonar and tagging devices but the government never heeded their advice.


MM Cat, Kvam's 18-metre shark-research vessel, currently sits at Aberdeen typhoon shelter, it's unique resources dormant. 'We are willing to loan it to the Government free of charge,' says Chan. 'We have the hardware but not the software. We're shark-net experts, not shark experts.'


'It'd be great to know what's going on,' says Frew, who would like to see relevant government departments trained to tag and identify sharks with battery-powered transmitters as part of an effort to beginning collecting raw data.


'Research and respect in this part of the world are sorely lacking; sharks here end up in a bowl,' says Frew. 'After all these attacks it's 2001 and we still have a blank screen. They've come and gone and we know nothing about them. It's an opportunity lost.'


Jaws watch


Below are some of the less endangered sharks in Hong Kong waters or those thought to be responsible for human attacks.


Great white shark: Widely distributed but sparsely populated, it's considered the world's largest predator, growing up to eight metres long and weighing up to 3,400kg. It's been implicated in local attacks but these were never confirmed. Most human attacks occur in estuaries.


Tiger shark: Second only to great whites in recorded attacks on humans, it's distinguishable by its vertical dark grey to black bars and is thought to be responsible for the majority of Hong Kong attacks. Growing in excess of seven metres and weighing more than 800kg, it eats anything: garbage like tyres and tin cans, carrion, other sharks, man.


Bull shark: Considered the most dangerous species of tropical fish as it is repeatedly implicated in attacks on humans, the bull has been both sighted and caught near Kadoorie Beach and Tuen Mun. 'There's quite a lot in the South China Sea,' says Rommy Cheung, who has been diving locally for 20 years as scuba-diving course director of International Elite Divers Training Centre. Growing up to 3.5 metres and more than 300kg, the bull shark will also venture into fresh water in search of food.


Hammerhead shark: Fifty years ago, hammerheads comprised the most sustainable local shark fishery. The practice of 'finning', killing them for their fins to be served in a traditional soup, is responsible for their demise. Noticeable for its distinct elongated, hammer-shaped head, it grows up to five metres long and weighs up to 400kg.


Grey shark: It is repeatedly incriminated in human attacks and is locally thought to be responsible for strikes on 'freedom swimmers' or illegal mainland immigrants, trying to enter Hong Kong in the 1960s and 70s, says Cheung, as the grey was the most commonly sighted shark in Mirs Bay back then. It grows to 2.5 metres and weighs up to 350kg. It's one of the few species that is active during the day and readily enters into a feeding frenzy pattern, at which time it may become quite dangerous.


Blacktip reef shark: A brown-coloured shark that's most easily recognisable by black tips on all dorsal fins. It prefers to inhabit shallow water around coral reefs and was thought to have a breeding ground in the waters just north of Chek Lap Kok. It grows up to two metres long and may become aggressive to spear fishers and has been reported to bite people wading in shallow water.


Nurse shark: A docile, tawny-coloured bottom-feeder with barbels (thin, fleshy, whisker-like organs on the lower jaw in front of the nostrils that sense touch and taste) and comb-like teeth, they grow up to four metres long and are sometimes seen for sale in local fish markets. They are generally harmless unless provoked. 'We see quite a few up in Mirs Bay,' says Cheung, 'though they are often not larger than a metre as they are heavily fished.'


Bamboo shark: A small, bottom-dwelling shark with brown and black vertical bands running the length of its body that grow little bigger than one metre long and isn't considered a human threat.


* All the shark species information is provided by Fishbase, www.fishbase.org, an information system of all known fish that caters to research scientists, fisheries managers and many others.


Shark facts


They're predators whose efficiency has evolved over nearly 400 million years. Nearly two-thirds of attacks on humans occur in less than two metres of water. They have extremely efficient vibration-monitoring systems and smell that can detect the movements of distressed animals for kilometres, or one teaspoon of blood in a million teaspoons of water. And they are long-lived, reaching maturity after about 30 years.


History of attacks


Before the most recent spate of shark attacks which began in 1991, the South China Morning Post's files contain more than 50 cases of people presumed drowned in the 1980s, with some of the bodies later washed up on shores partially eaten. Urban lore harks back to a spate of deaths in the 1950s of British military personnel.


More certain were the attacks inflicted upon the 'freedom swimmers', illegal immigrants from the mainland fleeing poverty and the Cultural Revolution in the 1960s and 1970s. Marine police dawn patrols off Sai Kung in Mirs Bay, in Starling Inlet where Shataukok rests on its north shore, and in the kilometre-wide channel that separates China from Ping Chau Island, would often turn up mutilated bodies.


Sharks weren't the only suspects. Barracuda and possibly mackerel, which can grow up to two metres long, were possible culprits in some incidents, as their bites are distinguishable for being usually smaller and much cleaner than sharks; there's little shaking and thrashing to tear off flesh.


What has never been ascertained is whether the victims had drowned before they were attacked.


1991


May 11 Multiple sharks sighted near Silverstrand Beach, Sai Kung.


May 25 Mainland fisherman Chan Yat-fai, 22, is thrown into the sea near Basalt Island when his sampan overturns in bad weather. He's later found dead with his arm bitten off.


June 8 In the first Hong Kong shark-attack death in 11 years, Yueng Kam-ho, 65, dies while swimming at Silverstrand. The 7am attack is believed to be the work of a tiger shark.


In an ensuing government-spearheaded hunt, four sharks are caught in the next three weeks. In Port Shelter near Shelter Island a fisherman catches a 2.5-metre, 100kg spinner shark, a species common around the Philippines and the Sea of Japan, but rare in Hong Kong waters. Spinners have been known to attack humans. The other three sharks are of an unidentified species caught in Mirs Bay off Sai Kung, average 80kg in weight, and are about one metre long.


1992


May 12 Nearly a year to the day, sharks are spotted again near Silverstrand Beach. It's believed that the same tiger sharks (if that's what they were and are) from the previous year have now developed a homing pattern for Silverstrand. However, there are no attacks on humans that year.


1993


May 31 Yan Sai-wah, 42, dies after his left leg is bitten off while swimming at Sheung Sze Wan, Sai Kung. Witnesses estimate that the killer is a seven-metre long monster.


June 2 A fisherman reports four sharks swimming 5km off Silvermine Bay on Lantau Island.


June 11 At 7.30am a furniture shop operator, Kwong Kong-hing, 61, ignores shark warnings and swims every morning as he has for the past three years at Silverstrand Beach. He is attacked in chest-deep water while his friend screams in terror from three metres away. He dies after his leg and hand are bitten off. Witnesses estimate the shark is five metres long.


It's the second death in 10 days prompting a new pastime: shark-spotting. Hordes of people now congregate daily at Silverstrand with binoculars and telescopes. As well, the Government scrambles to address the issue, forming the interdepartmental shark prevention committee.


June 13 The Discovery Bay Marina Club assistant supervisor sights two sharks at 10.20am about 70 metres away from the club.


Later that month, Vic Hislop, famed Australian shark-hunter, comes to Hong Kong to much fanfare, but bails out after two weeks after becoming infirm.


July 17 Two swimmers, aged 23 and 30, are killed at the resort of Xitung, near Shenzhen.


1994


February 14 Ten sharks are reported swimming off Silverstrand Beach, which is an unusual time of year for such sightings.


March The first shark nets are installed, at Silverstrand Beach, Clear Water Bay Second Beach, and Kadoorie Beach in Tuen Mun.


1995


May 31 A former Hong Kong swimmer in the Asian Games, physical education teacher Tso Kam-sun, 44, dies swimming near Silverstrand after his right leg is bitten off. It's thought to be the same shark that had terrorised the same waters two years to the day. The homing pattern theory is once again applied.


June 2 Hairdresser Herman Lo Cheuk-yuet, 29, screams in agony as his right thigh is mauled to the bone before he can be pulled from shallow water at Sheung Sze Wan. Two hundred beachgoers look on in horror as he dies.


June 13 Wong Kwai-yung, 45, a housewife and early morning swimming enthusiast, dies at Clear Water Bay First Beach after more than one shark rips off her left leg and left arm. From a helicopter, television cameras later record two big sharks swimming in the vicinity.


It's the third death in a fortnight and in response, the Government decides to recruit another expert but passes on Hislop. Local environmentalists had branded Hislop 'a vigilante on a killing spree', and with his feelings hurt, he vows never to return anyway.


Instead, the recruit is Dr George Burgess, who is now director of the International Shark Attack Files, which is based in Florida. Burgess puts together a brief report but ultimately recommends the Government commission an 18-month study which would track sharks using sonar. The Government ignores his advice.


1996


April 18 In two separate incidents, two mainland fishermen are attacked and die on the Chinese side of Mirs Bay. The water temperature is a cool 20 degrees Celsius.


April 19 Fishermen net a three-metre tiger shark - although it's not thought to be the killer - off the Brothers Islands near Tuen Mun.


Scientists and divers beseech the Government to start a long-delayed shark study.


2000


August Possible shark sighting in Mirs Bay off Sai Kung. Apparently, the animal was resurfacing often and swimming in a manner more similar to porpoises or dolphins.


Still, it's enough for local scientists to again urge the Government to initiate a shark study, but once again, to no avail.


2001


May 6 At about 10am, a woman on a boat in Deep Water Bay reports seeing two sharks, about 1.5 metres long. Nine shark-netted beaches are closed. Thousands of beachgoers are irate.


May 8 At 12.30pm, a woman in Deep Water Bay - it is not clear whether it's the same woman as two days prior - reports seeing seven or eight sharks swimming nearby. No beaches are closed. Government Flying Service helicopters and marine police are unable to confirm either day's report.


May 29 Swimmers are asked to stay out of the water at Deep Water Bay after three to four sharks are sighted coming from Repulse Bay.


At least 13 types of shark have been recorded in Hong Kong waters in the past 150 years, though now they are considered extremely rare, verging on extinction, says Andrew Cornish, co-author of Reef Fish Of Hong Kong.


These include the grey reef shark, whitecheek shark, silky shark, hardnose shark, spottail shark, blacktip reef shark, tiger shark, milk shark, grey sharpnose shark, bull shark, spadenose shark, great hammerhead shark and the smooth hammerhead shark.


Absent from the list is the great white, which has never been confirmed, says Cornish. Otherwise, five species - the grey reef, hammerhead, tiger, bull and silk sharks - are considered potentially dangerous to human. Although silkies are relatively small at two metres, they have been blamed for the deaths of many shipwrecked sailors during World War II.


Harmless whale sharks are also caught just outside Hong Kong waters sometimes and probably occur here from time to time, says Cornish.